/Engine/Source/Runtime/Core/Public/Misc/ConfigCacheIni.h
For a base ini name, gets the config cache filename key that is used by other functions like Find. This will be the base name for known configs like Engine and the destination filename for others.
Filename key used by other cache functions
[FString](API\Runtime\Core\Containers\FString) GetConfigFilename ( const TCHAR * BaseIniName )